package com.huaxingbankas.modules.tools;

import org.aspectj.util.FileUtil;

public class Digui {
	 public static void main(String[] args) {
		  double a=0,b=0;
		  for(int i=1;i<=100;i++){
		   if(i%2==1){
		   a=a+(double)1/i;
		   }
		   else{
		   b=b+(double)1/i;
		   }
		  }
		  System.out.println(a-b);
		 }
	
}